I asked the support staff about this, as Linux Version 7 *does* have the presentation tab (I'm guessing Windows V7 does, as well, but I don't have a windows box), and they said, in a nutshell "it's a beta, we're still testing it".
Fair enough, although if you set up a meeting with V6 on a Mac (which is apparently what you need to do) and send the "join presentation" link to your attendees, the link will automatically take them to a "join meeting" page geared towards V7. A bit annoying - why push a V7 "join meeting" page when the host of the meeting can't use V7? Your attendees need to click on a "join using previous version" link at the bottom of the page to join your meeting. So be sure and mention this in the "join meeting" email you send to your attendees. If they don't know to click the "join previous version" link, they'll probably get pretty frustrated.
